If history is any guide, sanctions imposed by the Obama administration on Russian officials, individuals and a bank as punishment for Russia’s actions in Ukraine are unlikely to defuse a crisis that has been likened to the Cold War.

Syria, North Korea and Cuba stand out as stark examples of countries where years — even decades — of Western sanctions have failed to moderate the targeted regime’s behavior.

In Syria, Bashar Assad’s forces show no sign of ending a 3-year-old civil war that has killed more than 100,000 and displaced close to 9 million Syrians.

In Cuba, the Castro brothers cling to power despite five decades of U.S. sanctions.

And in North Korea, sanctions have done little to convince Kim Jong-un to give up his quest for nuclear weapons.

“Most open sanctions, a slap in your face, fail,” said Donald Losman, lecturer in international affairs at George Washington University’s Elliott School of International Affairs.

“These ones, too, will fail,” he added, referring to sanctions the U.S. has imposed on the Russians this month in response to Russia’s military intervention in Ukraine and its annexation of the Crimean Peninsula.

The U.S. has so far imposed sanctions on 31 Russians and Ukrainians, and has frozen the assets of Bank of Rossiya, a Russian bank with $10 billion in assets. The European Union has penalized 33 individuals.

Those on the blacklist are barred from traveling to the U.S. or to any of the 28 members of the European Union, and any assets they might have in U.S. or European banks have been frozen. It is unclear whether these individuals have assets in the U.S. or EU.

“The sanctions that have been imposed so far on Russian entities and individuals have been very, very modest; certainly not enough to compel Russia to change its behavior,” said Daniel Drezner, professor of international politics at the Fletcher School at Tufts University.

“But even if you imposed comprehensive sanctions on Russia, I would be extremely doubtful that it would change their course of action at this point,” he added.

Sanctions, regardless of their bite, will not be enough to convince Russian President Vladimir Putin to give up the Crimean Peninsula, say analysts and former officials.

“[The annexation of Crimea] is wrong, it is illegal, but I don’t think President Putin will give back Crimea,” said R. Nicholas Burns, who served as the under secretary of state for political affairs in President George W. Bush’s second term.

“Unfortunately, it seems like a done deal,” he added.

If Russian forces were to withdraw from the Crimean Peninsula, Mr. Putin “wouldn’t be in power the next day because he has put his personal stake on this,” said Mr. Drezner.

Mr. Putin has responded to U.S. pressure with his own sanctions on U.S. lawmakers and officials, and by formalizing Russia’s annexation of the Crimean Peninsula. On Monday, Russian troops took over a naval base bases in Crimea as Ukraine’s interim president, Oleksandr Turchynov, ordered his troops out of the peninsula.

Michael McFaul, who served as the U.S. ambassador to Russia until February, said he doesn’t think the U.S. sanctions currently in place can change Mr. Putin’s “decision-making.”

“The sanctions are designed to make people pay a price, but it’s not designed to change their behavior,” Mr. McFaul, who is now the Hoover fellow at Stanford University, said in a Foreign Affairs magazine phone briefing with reporters this week.

Russian officials have scoffed at U.S. pressure with comments that have borne echoes of Moscow’s disdain for sanctions in the past.

However, years of U.S. and European sanctions are credited with persuading Iran to agree to negotiations on its nuclear program. The diplomatic effort is ongoing.

It took a concerted effort by the U.S. and the European Union to achieve this result with Iran. European nations have been less enthusiastic about punishing Russia, on whom they rely for their energy needs.

If the West slaps sanctions against the Russian economy, the impact on the U.S. — which does not have a significant trade relationship with Russia — would not be nearly what it would be on Europe.

“Sanctions in the modern global economy will be effective when major economies combine. That’s what you saw in Iran; you have not yet seen that in Russia,” said Mr. Burns.

Getting Europe on board

Mr. Obama is visiting Europe this week in a trip partly intended to shore up the Western alliance against Russia.

A lot is riding on the president’s ability to convince the European leadership to join the U.S. in taking a tough stand against Russia, said Mr. Burns, who is currently a professor of international relations at Harvard University’s Kennedy School of Government.

“If the Europeans aren’t convinced … then of course U.S. sanctions on the Russian economy will be far less effective if they are not joined by EU sanctions,” he said.

The Obama administration’s sanctions blacklist includes officials linked to the Kremlin and the so-called cronies, Russians with close ties to Mr. Putin.

“The idea is that they should put pressure on the Kremlin while diplomatic [efforts] are underway to reach a negotiated solution to the crisis,” said Clara Portela, assistant professor of political science at Singapore Management University who has closely studied the impact of European sanctions around the world.

The ‘real threat’

Mr. Obama is right to be taking the steps he has, said Mr. Burns. Announcing a second round of sanctions last week, Mr. Obama said he had signed a new executive order that gave him the authority to impose sanctions on key sectors of the Russian economy.

It is these sanctions that, if imposed, could cause significant pain to the Russian economy.

“It is a real threat, because Russia has an economy that cannot run successfully unless it is integrated with the rest of the world,” said Mr. Burns. “This is not North Korea that is content to live in isolation from the rest of the world. Russia’s economic health depends on trade and investment.”

The U.S. and European Union must carefully calibrate pressure on Moscow, say analysts.

Too little will fail to produce the outcome the West seeks: that Russia deescalate the situation and promise to stop meddling in eastern Ukraine.

Too much could cause Mr. Putin to shut off cooperation with the U.S. on important global issues, particularly on negotiations on Iran’s nuclear program.

Sanctions can also have the unintended consequence of producing what Carol Joy Gordon, a professor at Fairfield University, said is a “‘rally around the flag’ response, where the population of the targeted country do not view sanctions as moral leadership, but as an intervention in violation of their sovereignty.”

Senior Obama administration officials in a background call with reporters last week defended their use of sanctions, and said more measures are being crafted that would minimize the pain to the U.S. and its European partners.

“Sanctions build over time. They’re very powerful,” said a senior administration official on the call, “and people may think that they are a mere wrist slap; I can assure them that they are not.”